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500 个结果
  • 简介:在分析了直流电机驱动芯片L298N的性能、结构的基础上,结合SPCE061AEMUBOARD单片机(61板),介绍实现驱动直流电机的转正反一种简单方法.文中给出了控制原理图,还给出来了控制直流电机正反转驱动程序。实际测试表明,利用该方法设计的直流电机驱动系统具有硬件结构简单、软件编程容易。

  • 标签: 直流电机 单片机 L298N
  • 简介:NineteenL-N-2-hydroxyethylaminoacidsandL-N,N-bis(2-hydroxyethyl)aminoacidswerepreparedfromthereactionofchlorohydrinwithL-alanine,L-valine,L-leucine,L-isoleucine,L-phenylalanine,L-serine,L-thrcunine,L-glutamicacid,L-asparticacidandglycine.L-N,N,N’,N’-tetra(2-hydroxyethyl)cystinewaspreparedbythereactionofL-cystinewithchlorohydrin.

  • 标签: hydroxyethyl PHENYLALANINE LEUCINE GLYCINE tetra solubility
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  • 简介:本文主要考察湖南境内湘语九个方言点的“V+X+NL)”结构类型和地理类型。湖南方言“V+X+N(1,)”的类型共有四种,除了普通话中常见的句型“在+N(1.)”、“V+到+N(1.)”外,还有“V+体貌助词州(L)”和“V+体貌助词+在+N(1.)”。

  • 标签: 湘语 V+X+N(L) 结构类型 地理类型
  • 简介:ByusingOH-terminatedpolyaryletherdendrimerandN-Fmoc-glycineasrawmaterials,thedendriticpolyarylether2-aminoacetate(G3-NH2)wassynthesizedviatwostepreactions.G3-NH2asamacroinitiatorforthering-openingpolymerizationofγ-benzylL-glutamateN-carboxyanhydridewasinvestigated.Itisfoundthattheresultingcopolymerspossessedrelativelyhighmolecularweightandnarrowmolecularweightdistribution(1.12

  • 标签: 开环聚合反应 γ-苯甲基L-谷氨酸酯N-羧基酐 多肽 枝晶
  • 简介:Inthispaperwewillshowthatifanapproximationprocess{Ln}n∈Nisshapepreservingrelativetotheconeofallk-timesdifferentiablefunctionswithnon-negativek-thderivativeon[0,1],andtheoperatorsLnareassumedtobeoffiniterankn,thentheorderofconvergenceofDkLnftoDkfcannotbebetterthann2evenforthefunctionsxk,xk+1,xk+2onanysubsetof[0,1]withpositivemeasure.Takingintoaccountthisfact,wewillbeabletofindsomeasymptoticestimatesoflinearrelativen-widthofsetsofdifferentiablefunctionsinthespaceLp[0,1],p∈N.

  • 标签: 渐近估计 N-宽度 线性相关 次可微函数 逼近过程 线性关系
  • 简介:ThecommutatorsofsingularintegraloperatorswithhomogeneouskernelΩ(x)/|x|^narestudied,whereΩishomogeneousofdegreezero,andhasmeanvaluezeroontheunitsphere.ItisprovedthatΩ∈L(logL)^(k+1)(S^(n-1))isasufficientconditionsuchthatthek-thordercommutatorisboundedonL^2(R^n).

  • 标签: 转接器 单一积分算子 有界平均振动 傅里叶变换
  • 简介:文中阐述了“N+X”冗余模块式UPS的由来、发展、定义、可靠性和可用性以及实现高可靠性和高可用性的产品类型,并将其与“1+1”冗余式UPS进行了比较。

  • 标签: 冗余 模块式 可靠性 可用性
  • 简介:介绍了一种采用STC89C52单片机和L298设计的智能循迹小车控制系统,给出了小车控制系统的总体设计方案,详细论述了小车控制系统的硬件结构原理,分析了传感模块循迹代码、转向灯和电机的控制代码,给出了小车能够平稳准确循迹的软件设计思想。

  • 标签: 电机 循迹 控制
  • 简介:摘要:基于L波段250W的GAN功放管,本文成功实现一款800W的固态脉冲功率放大模块;实验结果表明,该脉冲功率放大器可应用于L频段高占空比脉冲功率发射机中。

  • 标签: L波段GAN功率放大器高占空比
  • 简介:N-acetyl-D-methionine,NaAcandtheremainsofN-acetyl-L-methioninedramaticallyaffectthepurificationofL-methioninewhenpurifiedfromthemixtureofenzymaticallydeacylatedN-acetyl-DL-methionine,leadingtoalowyieldconventionally.Here,thispaperreportsasuccessfulseparationandpurificationofbothL-methionineandN-acetyl-D-methioninebyanHion-exchangecolumn.ThepH,L-Metconcentrationandtheratiobetweenthecontentofsodiumcationandtheion-exchangecapacitywereoptimizedtoobtainthemaximumyield.Experimentalresultsindicatethat,undertheoptimizedconditions,theyieldsofL-methionineandN-acetyl-D-methioninecanreachashighas85%and75%,respectively.

  • 标签: L-蛋氨酸 N-乙酰基-D-蛋氨酸 N-乙酰基-DL-蛋氨酸 分离 纯化 脱酰作用
  • 简介:让b=(b_1,···,b_m),b_i∈Λ_(β_i)(R~n),1≤i≤m,0<β_i<β,0<β<1,[b,T]f(x)=∫_(R~n)(K是aCalderon-Zygmund的b_1(x)-b_1(y))···(b_m(x)-b_m(y))K(x-y)f(y)dy,核。在这篇论文,我们显示出那[b,T]从L~p(R~n)toF_p~被围住(β,∞)(R~n),以及[b,从L~p(R~n)的I_α]到F_q~(β,∞)(R~n),在哪儿1/q=1/p-α/n

  • 标签: 多线性转换器 Calderon-Zygmund核心 LIPSCHITZ空间 TRIEBEL-LIZORKIN空间
  • 简介:ObjectivesToevaluateantihypertensiveefficiencyandsafetyofanewdomesticofL-&N-typeCa^2+antagonist-eilnidipinewithimidaprilasapositivecontrol.MethodsAfter2weeks'placebowashingout,22patientsweretreatedwitheilnidipine5mgdailyand27patientsweretreatedwithimidapril5mgdaily.4weekslater,ifpatient'ssittingdiastolicbloodpressureisover90mmHg,his/herdosagewasdoubledforanother4weeks,theothersmeasuringupremainedtheirdosageunchangedforanother4weeks.Bloodpressure,heartrate,bloodandurineroutineexamination,serumglucose,serumchemicalexaminationincludingtotalcholesterol,triglyceride,HDL,LDL,transaminase,creatineetcandsidereactionswererecordedbeforeandafterthetrial.Datawereanalyzedstatistically.ResultsAfter8weeks'treatment,bloodpressurewassignificantlydecreased(P<0.05)inbothgroups,andthetwomedicineshadsimilarantihypertensiveeffects.Furthermore,thereducingofheartratewasstatisticallysignificantcomparedwithbaseline(P<0.01)inthecilnidipinegroup,butnotintheimidaprilgroup.Thenegativechronotropiceffectofcilnidipinehadlittleeffectoncontinuingthetherapy.Therewerenochangesonbloodandurineroutineexaminationandserumlipid,serumglucose,creatine,transaminaseandetcinbothgroups.Theirsidereactionsweremildandwell-tolerated.ConclusionsCilnidipinehasacon-vincingantihypertensiveeffectsimilartothatofimi-dapril.Especiallycilnidipinemaybeadministeredtopatientswithrelativelymildtachycardia.

  • 标签: 钙拮抗剂 西尼地平 抗高血压药物 药物不良反应
  • 简介:TheauthorsdiscussproblemsofapproximationtofunctionsinL^2(R^n)andoperatorsfromL^2(R^n1)toL^2(R^n2)byRadial-BasisFunctions.TheresultsobtainedsolvetheparblemofcapabilityofRBFneuralnetworks,abasicprobleminneuralnetworks.

  • 标签: 径向基函数 中性网络 逼近函数 算子
  • 简介:为了研究射影平面网格图的L(2,1)—标号,通过归纳综合的方法,研究了当3≤m≤8,3≤n<6时,射影平面网格图Gm,nL(2,1)—标号问题,得到了以下结果:(1)G3,3的L(2,1)—标号数为8;(2)当3≤m≤8,3≤n<6时,Gm,nL(2,1)—标号数的上界为9。

  • 标签: L(2 1)-标号 L(2 1)-标号数 射影平面网格图